I say its very nice for first map. You have all the basic things that one playable map require - CT and T spawnpoints , lights, blocks for cover and some group object with textures. The things that you need to focus now is:
1. How to optimise your map, so players can play without laggs - you can try adding NULL texture to the places that players cant see in game, you can tie all of your blocks to func_detail to make them not create needless shadows and use few lights with high brighness.
2. Use better textures and scale them properly, you don't need them to fit entirely into the wall, but just to look as good as possible.
3. Create smaller spawnpoints . You don't need big open space for spawns and you only need about 10 spawn enitities for each team.
Thats for now , i hope to see more of your work in future.

So I decided to see the map and made couple screenshots in case someone wanna see them here we go.
This is the whole map pretty much, there is nothing more to see, I hope next time you can do a better one.